Piles are introduced into the seabed by means of drilling or ramming, in order to be used there as a foundation for marine construction work, in particular for offshore wind energy plants. The foundations generally consist of one or more piles. In the case of a foundation with only one pile, a single pile or monopile is referred to. In the case of a foundation comprising a plurality of piles, the latter is often introduced into the bed using so called templates. Foundations of this type are also called jacket foundations or tripod foundations.
In the case of a tripod foundation, the construction is assisted by a structure having three diagonal struts with additional horizontal reinforcements at the level of the seabed. At the ends of the struts facing the seabed, the latter are connected to piles introduced into the bed.
In the case of a jacket foundation, the construction is anchored to a framework structure made of hollow profiles, which is called a jacket. The framework structure is anchored using the piles introduced into the seabed. At least three piles are generally provided for a jacket foundation.
When using a tripod or a jacket, it has logistically proven to be advantageous if the piles are firstly introduced into the seabed, for example using a template, and at a later time, the jacket or tripod is connected to the piles, independently of the introduction of the piles in terms of time.
During the drilling and vibration ramming in the seabed, in particular during impact ramming of offshore piles, considerable sound emissions are emitted into the surrounding water from the piles introduced into the seabed, but also from the seabed. For the fish and sea mammals living in the water, these sound emissions can be harmful and life-threatening. The sound is produced at the friction face of the pile and seabed and is transmitted thereby into the water surrounding them.